disregarding air resistance, what is the speed of a ball dropped from 12 feet just before it hits the…

disregarding air resistance, what is the speed of a ball dropped from 12 feet just before it hits the ground? (use 1 ft = 0.30 m, and use g = 9.8 m/s².) 2.4 m/s 8.4 m/s 10.8 m/s 15.3 m/s

disregarding air resistance, what is the speed of a ball dropped from 12 feet just before it hits the ground? (use 1 ft = 0.30 m, and use g = 9.8 m/s².) 2.4 m/s 8.4 m/s 10.8 m/s 15.3 m/s

Answer

Explanation:

Step1: Convert height to meters

First, convert 12 feet to meters. Given 1 ft = 0.30 m, so $h=12\times0.30 = 3.6$ m.

Step2: Use the kinematic - equation

We use the kinematic equation $v^{2}=v_{0}^{2}+2ah$. The ball is dropped, so $v_{0} = 0$ m/s, $a = g=9.8$ m/s² and $h$ is the height. Substituting the values into the equation: $v^{2}=0 + 2\times9.8\times3.6$.

Step3: Calculate the speed

$v^{2}=2\times9.8\times3.6=70.56$. Then $v=\sqrt{70.56}=8.4$ m/s.

Answer:

8.4 m/s